Frik Sundstøl

Supplementation of graded levels of Desmodium intortum hay to sheep feeding on maize stover harvested at three stages of maturity 1. Feed intake, digestibility and body weight change.

Feed intake, digestibility and body weight change of lambs fed basal diets of maize stover harvested at three stages of maturity and supplemented with graded levels (0, 150, 300 and 450 g per head per day) of desmodium (Desmodium intortum cv. Greenleaf) hay were studied. The maize stovers were harvested at 30, 22 and 12% grain moisture content which were designated as stages I, II and III, respectively. The crude protein (CP) content of the stovers showed a decreasing trend whereas the fibre contents showed an increase from stages I to III. The desmodium hay had higher CP, phenolic compounds, calcium, sulphur and manganese contents and lower fibre (neutral and acid detergent fibres, cellulose and hemicellulose) contents than the stovers. Maize stover, total dry matter (DM) and organic matter (OM) intake showed a decreasing trend (p>0.05) with increasing stage of maturity of the stover. The CP intake was significantly higher (p 0.05) with increasing stage of maturity. Crude protein digestibility and the intakes of digestible

The effect of stage of maturity on yield and quality of maize grain and stover

Abstract Stage of maturity at the time of harvest is considered as one of the factors influencing the nutritive value of crop residues. Thus this study was carried out to assess the effect of harvesting maize at different stages of grain maturity on yield and quality of maize grain and stover. The maize crop was harvested at grain moisture content of 28–30, 20–23 and 10–12%, which were designated as Stages I, II and III, respectively. Grain yield, standardised to 12.5% moisture content, showed an increasing trend, whereas cob, stover, total crop residue and total biomass dry matter (DM) yield showed a decreasing trend with increasing stage of maturity (p>0.05). The declining trend in stover yield with increased stage of maturity was due mainly to leaf loss. There was a significant decrease (p

Studies on untreated and urea-treated rice straw from three cultivation seasons: 3. Histological investigations by light and scanning electron microscopy

Straw of Shan-you 63 (SY63), a middle season rice variety with a high silica content, low degradability and good response to urea treatment, was used in an attempt to detect histological reasons of its low degradability and good response to urea treatment. The morphological differences of rice blade, sheath and stem were studied, whereas blade and sheath were used for studies of the treatment effect. Five per cent and 10 per cent urea were applied for studies of the urea treatment effect. Untreated and sodium hydroxide treated samples (1.5% NaOH solution) were included as negative and positive control, respectively. Light microscope (LM) and scanning electron microscope (SEM) were used for investigation of the histology and study of images. The results indicated that silica was deposited in epidermis polymerised with cuticle waxes to become a barrier to rumen microbial attack. This cuticle wax layer seemed to be affected by urea treatment. The absence of cuticle wax layer and epidermis on the inner surface of stem could explain its better degradability compared with sheath and blade. The inner surface of sheath also lacked the cuticle wax layer but had an epidermis layer which may explain why the sheath responds more to urea treatment than does blade which has cuticle wax layers on both sides. Urea treatment affecting the cuticle wax layer seems to enhance the digestibility of parenchyma tissue through swelling of the wall of parenchyma cells and cracking of the wall of vascular tubes. The results indicated that urea treatment caused both physical and chemical changes in straw tissues and cell walls.

Feeding value of enset (Ensete ventricosum), Desmodium intortum hay and untreated or urea and calcium oxide treated wheat straw for sheep

Feed intake, in vivo nutrient digestibility and nitrogen utilization were evaluated in male sheep fed different fractions (leaf, pseudostem, corm, whole plant) of enset, untreated or 2% urea- and 3% calcium oxide- (CaO or lime) treated wheat straw and Desmodium intortum hay as sole diets. All feeds, except D. intortum hay and enset leaf had low crude protein (CP) content. Non-fiber carbohydrate contents were higher in enset fractions, especially in pseudostem and corm relative to other feeds. Enset leaf and pseudostem had high calcium, phosphorus and manganese contents. Corm, whole enset and D. intortum hay were rich sources of zinc. Daily dry matter and CP intakes were higher (p < 0.05) in sheep fed D. intortum hay (830 and 133 g, respectively) than those fed pseudostem (92 and 7.8 g, respectively). Organic matter digestibilities were highest for corm (0.780) and whole enset (0.776) and lowest for D. intortum hay (0.534) and untreated wheat straw (0.522). The CP digestibility ranged from 0.636 in D. intortum hay to 0.408 in corm. Nitrogen (N) balance was highest (p < 0.05) in D. intortum hay (10.4 g/day) and lowest in corm (-1.3 g/day). Enset leaf could be a useful protein supplement whereas the pseudostem and corm could be good sources of energy.

Prediction of feed intake, digestibility and growth rate of sheep fed basal diets of maize stover supplemented with Desmodium intortum hay from dry matter degradability of the diets

The in sacco dry matter (DM) degradability of diets based on maize stover harvested at three stages of maturity and supplemented with graded levels of desmodium (Desmodium intortum cv. Greenleaf) hay were estimated from degradability of the individual feeds and their corresponding DM intake. The estimated DM degradability of the diets was used for prediction of DM intake (DMI), digestible DM intake (DDMI), DM digestibility (DMD) and growth rate of sheep feeding on the diets. The desmodium hay had significantly higher (P<0.05) DM disappearance than the maize stovers after 4, 8, 16, 24 and 48 h of incubation, as well as higher washing loss (A), degradation rate (c value) and effective DM degradability (ED) than the maize stovers. The washing loss was lowest in maize stover harvested at stage III and, as a consequence, the washing loss of the diets showed a significant decrease (P<0.05) with increasing stage of maturity of the stovers. The DM disappearance after 48 h incubation, washing loss and degradation rate showed a significant increase whereas the insoluble, but potentially degradable, fraction (B) showed a significant decrease (P<0.05) with increasing level of supplementation. The DM disappearance after 24 and 48 h of incubation, washing loss, ED and degradation rate showed strong positive correlation whereas the insoluble, but potentially degradable, fraction showed a negative correlation with DMI, DMD, DDMI and growth rate. On the other hand, the DM disappearance after 96 h of incubation, potential degradability and the lag phase showed very low correlation with these parameters. In general, the washing loss, ED and the DM disappearance after 24 and 48 h of incubation were found to be simple and reliable predictors of DMI, DDMI, DMD and growth rate. However, the use of the A, B and c values simultaneously in a multiple regression gave a more precise prediction of feed intake, digestibility and growth rate.